Method of monitoring network and application performance by analyzing web clients and web servers

ABSTRACT

A system and method for monitoring network and application performance. In one embodiment the method comprises logging information on network interface card (NIC) events involving a web page transaction, logging information on web server events involving the web page transaction, logging information on client browser events involving the web page transaction, collecting the information on NIC events, the information on web server events, and the information on client browser events on a collector server, and correlating the information on NIC events, the information on web server events, and the information on client browser events. In a further embodiment, correlating the information may comprise correlating the information on NIC events with the information on web server events by grouping the events by a client address and by a server address and then matching pairs of NIC events and web server events by time and data transfer size. Correlating the information may also comprise correlating the information on client browser events with the information on web server events by a color ID.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the field of computer processing and, more particularly, to the monitoring of web page transfers between web clients and servers.

2. Description of the Related Art

In the information technology (IT) departments of modern organizations, one of the biggest challenges is meeting the increasingly demanding service levels required by users. With more and more applications directly accessible to customers via automated interfaces such as the world wide web, “normal” business hours for many enterprises are now 24 hours a day, 7 days a week. As a result, the importance of monitoring and maintaining the quality of web applications and web services has increased dramatically.

Web applications and web services may be monitored on both the server side and the client side. Monitoring the server side may comprise monitoring the performance of a single node web server, or monitoring the performance of dozens or hundreds of nodes organized into multiple tiers of web servers, application servers and databases. Monitoring a multi-tier server installation may comprise monitoring communications within a given tier and communications between tiers. The monitored performance of the server side may further be correlated to distinct web page requests, client network addresses, and the historical performance of the server side.

Client side monitoring may comprise monitoring the performance of a web browser in rendering and displaying a web page. However, client side monitoring often occurs independently of server side monitoring, with no correlation between the performance data. Furthermore, even when client side monitoring occurs, only a select subset of clients may be monitored, and only in certain artificial scenarios which may not be indicative of real-world usage. Accordingly, such client side monitoring may be of limited applicability in presenting a complete picture of all transactions between the client and server.

SUMMARY OF THE INVENTION

Various embodiments of a system and method for monitoring network and application performance are disclosed. In one embodiment the method comprises logging information on network interface card (NIC) events involving a web page transaction; logging information on web server events involving the web page transaction; logging information on client browser events involving the web page transaction; collecting the information on NIC events, the information on web server events, and the information on client browser events on a collector server; and correlating the information on NIC events, the information on web server events, and the information on client browser events to monitor performance of the web page transaction.

In a further embodiment, correlating the information may comprise correlating the information on NIC events with the information on web server events by grouping the events by a client address and by a server address and then matching pairs of NIC events and web server events by time and data transfer size.

In one embodiment, logging information on NIC events comprises utilizing a NIC agent, logging information on web server events comprises utilizing a web server agent, and logging information on client browser events comprises utilizing a browser agent. The browser agent may be operable to log a time at which a request for a web page was sent, a time at which a response including the web page was received, a time at which the web page completed rendering, and a color ID associated with the web page. In an additional embodiment the browser agent may further be operable to log whether the web page was abandoned before the web page completed rendering.

In another embodiment, the method may further comprise displaying correlated information to an end user. In various embodiments displaying the correlated information may comprise displaying information on the overall operation of one or more web servers, and displaying information on the web page transaction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of one embodiment of a performance management system.

FIG. 2 is a block diagram of one embodiment of a computer system.

FIG. 3 is a block diagram of another embodiment of a performance monitoring system.

FIG. 4 is a block diagram of an exemplary web page.

FIG. 5 is a flowchart illustrating one embodiment of a method for collecting transaction data.

FIG. 6 is a flowchart illustrating one embodiment of a method for correlating transaction data.

FIG. 7 is an exemplary diagram of one embodiment of a display of correlated transaction data.

While the invention is susceptible to various modifications and alternative forms, specific embodiments are shown by way of example in the drawings and are herein described in detail. It should be understood, however, that drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the invention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.

DETAILED DESCRIPTION

A performance management system may include one or more software programs for application performance management. By continuously monitoring key components and/or applications of computer systems, the performance management system may act to detect and correct performance problems among applications and other system components in a complex computing environment. The performance management system may provide performance management in a variety of stages, such as: identification of symptoms that could indicate a performance problem, identification of sources or locations of problems, discovery of root causes of problems, recommendation of measures to address the root causes and improve performance, and verification that the measures have achieved desired goals. By defining baselines for “normal” application behavior, the performance management system may automatically detect degradation based on those established norms.

In one embodiment, the performance management system may be implemented in a variety of versions, each of which is customized for management of a particular class of target software: e.g., various products from PeopleSoft, Inc.; Oracle® database management software and related applications; web-based applications; SAP®; various products from Siebel Systems, Inc.; ClarifyCRM™; J2EE™; and other suitable targets. Furthermore, each of the versions may be implemented on one or more computing platforms (e.g., Solaris running on Sun Microsystems™ hardware, or a Microsoft Windows® OS running on Intel-based hardware). As used herein, the term “performance management system” is intended to include all of these disparate, customized software programs. The performance management system may further include a system for collecting and analyzing performance data from client systems, and for correlating said data with performance data collected from the target systems described above.

FIG. 1 is an architecture diagram of a performance management system 100 in an exemplary configuration. As illustrated in FIG. 1, the performance management system 100 may include components such as a measurement component 102 (including various agent modules 104 a, 106 a, and 108 a), a discovery component 112, a console component 120, and a performance warehouse 110. The various components of the performance management system 100 may reside on the same computer system, on different computer systems, or on an arbitrary combination of computer systems. An exemplary computer system is illustrated in FIG. 2.

In one embodiment, the measurement component 102 uses agent software to capture performance metrics on servers running target applications. Specifically, measurement component 102 may capture data from various web servers, application servers, and database servers, components within a server such as a network software module or a network interface card, and end user applications such as client browsers. The measurement component 102 may thus provide a “breadth-wise” view of performance across multiple technology tiers (e.g., web clients, web servers, networks, application servers, database servers, storage servers, etc.). The measurement component 102 may measure, for example, end-to-end response times from the viewpoint of a user. The measurement component 102 may also measure segmented response times from tier to tier and may therefore indicate the location of performance problems in a particular tier.

In one embodiment, a “base” version of the measurement component 102 may provide monitoring of a limited set of targets (e.g., TCP/IP-based applications). The functionality of the measurement component 102 may be augmented with optional agent modules that are customized to gather and analyze data for particular targets (e.g., web clients, web servers, networks, application servers, database servers, storage servers, etc.). For purposes of illustration and example, three agent modules 104 a, 106 a, and 108 a are shown. Other combinations of agent modules may be used in other configurations.

In one embodiment, the discovery component 112 provides identification and resolution of root causes of performance degradation. By permitting a user to “drill down” through various tiers of hardware and software (e.g., individual servers), the discovery component 112 may provide a “depth-wise” view of performance within each of the tiers that a target application crosses. The discovery component 112 may further indicate steps to be taken to fix current problems or avoid future problems.

In FIG. 1, each of the server blocks 104 b, 106 b, and 108 b within the discovery component 112 are intended to represent installations of agent software on the respective servers. For example, the three database server blocks 104 b represent three agent software modules associated with three respective database server installations. Likewise, the two application server blocks 106 b represent two agent software modules associated with three respective application server installations, and the four storage server blocks 108 b represent four agent software modules associated with four respective storage server installations. The combination of servers 104 b, 106 b, and 108 b is provided for purposes of illustration and example and is not intended to be limiting.

In one embodiment, the console component 120 includes a “watchdog” layer that communicates key performance indicators, such as exceptions to service level agreements (SLAs), to appropriate users at appropriate times. The console component 120 may include functionality 122 for establishing SLAs and other thresholds. The console component 120 may include functionality 124 for reporting and charting. The console component 120 may include functionality 126 for providing alerts. Therefore, the console component 120 may function as a management console for user interaction with the measurement component 102 and discovery component 112.

In one embodiment, the performance warehouse 110 includes a repository of performance metrics which are accessible to the other components in the performance management system 100. For example, the historical data in the performance warehouse 110 may be used by the other components to provide short- and long-term analysis in varying degrees of detail.

The performance management system 100 of FIG. 1 may be executed by one or more networked computer systems. FIG. 2 is an exemplary block diagram of such a computer system 200. The computer system 200 includes a processor 210 and a memory 220 coupled together by communications bus 205. The processor 210 can be a single processor or a number of individual processors working together. The memory 220 is typically random access memory (RAM), or some other dynamic storage device, and is capable of storing instructions to be executed by the processor 210. The memory 220 may store temporary variables or other intermediate information during the execution of instructions by the processor 210. The memory 220 may store operating system (OS) software to be executed by the processor 210.

In various configurations, the computer system 200 may include devices and components such as a keyboard & mouse 250, a SCSI interface 252, a network interface card 254, a graphics & display device 256, a hard disk 258, and/or a CD-ROM 260, all of which are coupled to the processor 210 by a communications bus 207. The network interface card (NIC) 254 may provide a communications link to one or more other computer systems via a LAN (local area network), WAN (wide area network), interne, intranet, or other appropriate networks. It will be apparent to those having ordinary skill in the art that the computer system 200 can also include numerous elements not shown in the figure, such as additional storage devices, communications devices, input devices, and output devices, as illustrated by the ellipsis.

Turning now to FIG. 3, a diagram of another embodiment of a performance monitoring system is shown. As described above, performance monitoring system 100B may monitor key components and/or applications of computer systems, such as a NIC 254 and a web server 300. Web server 300 is operable to distribute a response to a request from one or more client systems 320A-C. A response may be a web page, image file, applet, media file, or other component of a web page, as will be described in further detail below. Furthermore, web server 300 may be operable to “color” each web page returned with a given color ID, which may in turn be used to correlate data from different sources, as will also be described in further detail below.

Web server 300 may further be operable to operate in tandem with a web server agent 302. Web server agent 302 may be operable to log information on responses sent from web server 300, including, but not limited to, the data transfer size of a response, the time a response was sent, the color ID associated with a response, and the network address a response was sent to. In one embodiment, web server 300 may be a computer system 200 of the type described above, with web server agent 302 executing as a separate program on web server 300. Alternatively, in another embodiment web server 300 may be a software application executing on a single computer system 200, or a cluster of computer systems 200, with web server agent 302 executing as a software program or filter (e.g., an ISAPI filter) in parallel with web server 300.

NIC 254 may also be monitored by a NIC agent 312, which is operable to monitor the responses sent by web server 300 through NIC 254. Specifically, in one embodiment NIC agent 312 may be operable to log information on each request and response which passes through NIC 254, including, but not limited to, the size of a request or response, the time a request or response was received or sent, and the network address a request or response was received from or sent to. In one embodiment NIC agent 312 may be a software program operable to log information on all requests or responses which pass between a tier of web servers 300 and a tier of network interface cards 254. Alternatively, in another embodiment NIC agent 312 may be a software or firmware program operable only to log information on individual data packets sent to or from a specific NIC 254.

Client systems 320A-C may also be computer systems 200 of the type described in FIG. 2, and may be connected to performance monitoring system 100B by interconnect 340. Interconnect 340 may be a local area network (LAN), a wide area network (WAN), the Internet, or any combination thereof. Each client system 320A-C may further comprise a client browser 330A-C (referred to generally as client browsers 330). Client browsers 330 may each be operable to send one or more requests for web pages, image files, applets, media files, or other components to web server 300, and to receive and render one or more corresponding responses from web server 300.

Each client browser 330 may further include one or more browser agents 332A-C (referred to generally as browser agents 332). Browser agents 332 may be lightweight programs executing on client browsers 330, and, in various embodiments, may be written in any of a number of different lightweight cross-platform scripting languages, including Java™ or Javascript™. In one embodiment each browser agent 332 may be operable to log information including, but not limited to, the time an associated client browser 330 requests a specific web page, the time the time browser 330 begins to receive the web page, if an end user abandons the web page before the web page completes rendering, at what time the browser 330 finishes rendering the web page, and the color ID associated with the web page. As will be described in further detail below, the logged information may later be correlated with information logged by web server agent 302 and NIC agent 312 to provide a complete picture of interactions between client browsers 330A-C, NIC 254, and web server 300.

Browser agents 332, web server agent 302 and NIC agent 312 may each further be operable to communicate the collected statistics to a collector server 310, which may in turn be operable to correlate and display the received statistics, as will be described in further detail below. In one embodiment, collector server 310 may be a computer system 200 of the type described above, and may be connected to various other components by interconnect 340. Alternatively, in another embodiment, collector server 310 may be part of performance monitoring system 100B and may be operable to communicate with other components as part of the performance monitoring system.

It is noted that in various embodiments, the number of client systems 320, client browsers 330, web servers 300, NICs 254, web server agents 302, NIC agents 312, and browser agents 332 may vary according to the implementation of the performance monitoring system 100B.

Turning now to FIG. 4, a block diagram of an exemplary web page 400 is shown. In one embodiment, web page 400 may be a static HTML file, while in another embodiment, web page 400 may be a dynamically assembled HTML file created in response to a database query. Web page 400 may include a plurality of embedded files, such as image files 420A-C, applet 430, and media file 440. In various embodiments, image files 420A-C may be JPEG files, GIF files, bitmap files, or any other type of image file. Applet 430 may be any type of lightweight program, such as Java™, Javascript™, or Microsoft.NET™. Media file 440 may be an audio clip, a video clip, or an embedded animation in a language such as Flash™. It is also noted that web page 400 may contain additional types of files, may contain any number of the file types described above, or may contain no embedded files of any specific type.

Web page 400 may also contain a browser agent 332. In one embodiment, browser agent 332 may be embedded in every web page 400 sent out by web server 300, while in another embodiment each web page 400 sent out by web server 300 may contain scripting code operable to retrieve a browser agent 332 from a specified location and install the browser agent 332 on the client browser 330 receiving the web page 400. In a further embodiment, the scripting code in web page 400 may only retrieve a browser agent 332 if no browser agent 332 is currently installed on the client browser 330 receiving the web page. In yet another embodiment, browser agent 332 may already be statically installed on a web browser 330, and may not be part of web page 400.

As described in further detail above, web server 300 may further be operable to color a web page 400 with a color ID 410. As will be described in further detail below, color ID 410 may be operable to uniquely identify a specific web page 400 and associated components sent from web server 300 to client browser 330. In one embodiment, color ID 410 may be a Java™ cookie, while in another embodiment color ID 410 may be an alphanumeric string embedded in the web page as a comment, or as part of an embedded script.

Turning now to FIG. 5, a flow chart of one embodiment of a method for collecting web transaction data is shown. In step 500, client browser 330 sends a request for a web page 400 to web server 300. In step 502, an associated browser agent 332 logs the time the request was sent to the web server 330. As will be described in further detail below, in one embodiment browser agent 332 may maintain one or more data structures per web page request which may later be used to collect and correlate information related to the web page request.

In step 504, a NIC 254 receives the request from client system 320, and in step 506, NIC agent 312 logs the time the request was received and the network address the request was received from. In step 508 the web server 300 returns a response to client browser 330 through NIC 254. As described above, in one embodiment web server 300 may include a color ID 410 in web page 400. In step 510 the web server agent 302 may log what time the web server 300 sent the response to the client browser 330, as well as the data transfer size of the response, the network address the response is being sent to, and the color ID associated with each web page response.

In step 512, NIC agent 312 logs the time each response is sent through NIC 254, the data transfer size of each response, and the destination address of each response. In step 514, the client browser 330 receives the response, and in step 516, the browser agent 332 logs the time the first byte of the response was received, as well as the color ID associated with the response. In one embodiment, the browser agent 332 may use the color ID associated with the web page as an index for all past and future data associated with the web page request process. For example, browser agent 332 may place the color ID of the received web page 400 and the time the web page was received in the same data structure as the time the original request for web page 400 was sent. In one embodiment browser agent 332 may then clear the color ID from the received web page.

In step 518, the client browser 330 renders the received web page 400. It is noted that in one embodiment rendering the received web page may comprise sending additional requests for components of web page 400 stored on web server 300. In turn, NIC 254 and web server 300 may receive the additional requests and return corresponding responses, while NIC agent 312 and web server agent 302 log the information associated with each additional request and response, as described above in steps 506, 510 and 512.

For example, the web page 400 received by client browser 330 may contain a reference to media file 440. Accordingly, client browser 330, as part of the rendering process, may send an additional request to web server 300 for media file 440, which may in turn result in NIC agent 312 logging the time the request for media file 440 was received by NIC 254, as well as the network address of the client browser 330 sending the request. Web server 300 may service the request by returning media file 440, while web server agent 302 and NIC agent 312 may both log the time the file was returned, the address it was returned to, and the data transfer size of the file. In various embodiments, any number of request/response cycles for web page components may occur during the web page rendering process.

In step 520 the browser agent 332 may log at what time the web page rendering process of client browser 330 completes, thereby completing the collection of information on the various events associated with a web page transaction. In step 522, collector server 320 may retrieve the collected information from browser agent 332, web server agent 302, and NIC agent 312. In one embodiment collector server 320 may also collect the network addresses of the web browser 330 and the web server 300 so that the collected data may be correlated as described below.

Turning now to FIG. 6, a flow chart of one embodiment of a method for correlating web transaction data is shown. In step 600 collector server 320 correlates all data retrieved from NIC agent 312 and web server agent 302 by matching all communication events between a web server 300 network address and a client browser 330 network address. For example, in one embodiment collector server 320 may place all communication events between a specific client/server IP address pair on a virtual timeline, thereby providing a complete picture of the time each response or request was received and sent.

In step 602, the collector server 302 further matches information logged by NIC agent 312 and web server agent 302 by time and data transfer size. In one embodiment, the collector server 302 may match time and data transfer size within certain predetermined tolerances. For example, as described above, collector server 320 may place all communication events between a specific client/server IP address pair on a virtual timeline. Collector server 320 may then match information on the timeline logged by NIC agent 312 with information on the timeline logged by web server agent 302 if the logged times each event was sent at are approximately equal, and if the logged data transfer size of each event is approximately equal. More specifically, in one instance web server agent may log sending a 21 kilobyte response at 13:05:43.158, while NIC agent 312 may log sending a 23 kilobyte response at 13:05:43.253. Accordingly, taking into account a certain amount of latency between the web server and the NIC, and a certain increase in data transfer size due to added error correction code, collector server 320 may match the logged information from the web server agent and the NIC agent as different perspectives on the same event.

It is noted that by repeating this process for all information paired by client/server network address, collector server 320 may be able to correlate all logged information from NIC 254 and web server 300 on one or more web page transactions. It is also noted that the tolerances of the time and size comparisons described above may differ according to various embodiments. For example, in one embodiment the expected latency between a response being sent by a web server 300 and the response being sent through a NIC 254 may be tens of milliseconds.

In step 604 collector server 320 matches all correlated data from the web server agent 302 with the data from browser agent 332 according to the color ID 410 of each web page 400. For example, as described above, in one embodiment web server 300 may be operable to send a web page 400 to a client browser 330 with a color ID 410 in the form of a Java cookie. Web server agent 302 may be operable to log the color ID associated with the web page 400, while browser agent 332 may be operable to log that a web page 400 with a given color ID 410 was received at a given time, and that the web page 400 subsequently completed rendering at another time. Accordingly, by matching the color ID 410 values logged by web server agent 302 and browser agent 332, collector server 320 may be operable to match all logged information regarding web page 400.

In step 606, collector server 320 displays information on one or more web page transactions in various formats. For example, in one embodiment, collector server 320 may be operable to piece together information on a complete chain of events regarding a specific web page transaction, including, but not limited to, the time at which client browser 330 requested the web page, the time at which NIC 254 received the request, the time at which web server 300 returned the requested web page 400, the time at which the web page 400 was sent through NIC 254, the time at which client browser 330 received the web page 400, and the time at which client browser 330 completed rendering the web page.

Furthermore, collector server 320 may be operable to correlate end-to-end data from multiple web servers 300, NICs 254, and client browsers 330 to provide a detailed representation of all web page transactions monitored by performance monitoring system 100B. For example, FIG. 7 illustrates an exemplary display of collected transaction data. In one embodiment, a panel 700 lists average response times for a specific web page, including the average time taken for the first byte of data to be received by a client browser 330 in response to a request, the average time taken by a client browser 330 to complete the web page rendering process after the first byte has been received, and the total time taken for a web page to be received and completely rendered. Field 710 shows each of the web page's sub-component URLs that contribute to the average times shown in panel 700. Accordingly, field 720 shows the time taken by one or more servers 300 to retrieve a corresponding URL, while field 730 shows the time taken by one or more NICs 254 to transmit the corresponding URL. Other fields associated with specific web pages and their sub component (URL) may also show various performance metrics.

It is noted that the above representation of web transaction activity may be utilized to isolate problematic components, improve efficiency and customer response time, and better allocate network resources. For example, in one embodiment a system administrator may determine that all web page requests serviced by a given web server 300 take an abnormally long time to return from the web server. Accordingly, the system administrator may determine that the web server 300 should be serviced or replaced. Furthermore, the system administrator may be able to determine what web pages were affected by the slow web server, and in turn determine which business units may be affected by a slowdown in the servicing of those web pages.

In another example, a web designer may determine that an abnormally high percentage of web page views are abandoned by customers in a specific before the page finishes rendering. Accordingly the web designer may redesign the web page to be more quickly rendered or more attractive for customers in the country in question.

In still another example a system administrator may be able to explore the overall operation of one or more web servers 300 by looking at aggregate performance statistics and “drilling down” to view end-to-end performance information on a specific web page transaction, thereby allowing the administrator to achieve a “hands-on” feel for the performance of a web transaction. It is also noted that the fields described above are purely exemplary, and that in various embodiments other data may be correlated and displayed in various different ways.

It is further noted that the method described above may be implemented, in various embodiments, as a lightweight mechanism operable to monitor every web page transaction carried out by one or more web servers 300. Furthermore, the method described above may be operable to monitor the performance of a plurality of client browsers 330 on a variety of platforms and operating systems, and to provide a complete, real-world representation of the end user client browser experience.

It is further noted that any of the embodiments described above may further include receiving, sending or storing instructions and/or data that implement the operations described above in conjunction with FIGS. 1-7 upon a computer readable medium. Generally speaking, a computer readable medium may include storage media or memory media such as magnetic or optical media, e.g. disk or CD-ROM, volatile or non-volatile media such as RAM (e.g. SDRAM, DDR SDRAM, RDRAM, SRAM, etc.), ROM, etc. as well as transmission media or signals such as electrical, electromagnetic, or digital signals conveyed via a communication medium such as network and/or a wireless link.

Although the embodiments above have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications. 

1. A method comprising: operating network interface card (NIC) agent software on a server computer, said NIC agent software operable to collect performance data indicative of NIC events involving a web page transaction, said NIC agent software customized to collect performance data on tiers of web servers and tiers of NICs; operating client agent software on a client computer, said client agent software operable to collect performance data indicative of client events involving the web page transaction, and said client agent software customized to collect performance data on tiers of web servers and tiers of NICs; collecting the information indicative of NIC events, the information indicative of client events; and correlating the information indicative of the NIC events, and the information indicative of client events, to monitor performance of the web page transaction, wherein correlating the information comprises correlating the information indicative of NIC events with the information indicative of client events by grouping events by a client address and by a server address and matching pairs of NIC events and server events by time and data transfer size.
 2. The method of claim 1 wherein the NIC agent software is further operable to log whether the web page was abandoned before the web page completed rendering.
 3. The method of claim 1 further comprising displaying correlated information to an end user.
 4. The method of claim 3, wherein displaying the correlated information comprises displaying information on the an overall operation of one or more web servers.
 5. A system comprising: a performance monitoring system comprising: a processor and a memory, wherein the memory stores program instructions executable by the processor operable to: log event information indicative of web server events involving a web page transaction, and log event information indicative of network interface card (NIC) events involving the web page transaction said event information specific to a software product; log event information indicative of sub-component uniform resource location events involving the web page transaction and remote servers, and a collector server operable to monitor performance of the web page transaction by: collecting event information indicative of web server sub-component uniform resource location (URL) events; collecting event information indicative of web server events, and event information indicative of NIC events; and correlating the event information indicative of NIC events with the web server events and sub-component URL events, wherein the collector server is operable to correlate the event information indicative of NIC events with the event information indicative of web server events by grouping events by a client address and by a server address and then matching pairs of NIC events and web server events by time and data transfer size.
 6. The system of claim 5, wherein the performance monitoring system comprises: an NIC agent operable to log the event information indicative of client browser events, a web server agent operable to log the event information indicative of web server events, and a browser agent operable to log the event information indicative of client browser events.
 7. The system of claim 6 wherein the browser agent is operable to log: a time at which a request for a web page was sent; a time at which a first byte of the web page was received; a time at which a response including the web page was received; a time at which the web page completed rendering; and a color ID associated with the web page.
 8. The system of claim 7 wherein the browser agent is further operable to log whether the web page was abandoned before the web page completed rendering.
 9. The system of claim 5 wherein the collector server is further operable to display correlated event information to an end user.
 10. The system of claim 9, wherein the collector server is further operable to display information on an overall operation of one or more web servers.
 11. The system of claim 9, wherein the collector server is further operable to display information on the web page transaction.
 12. A non-transitory computer readable storage device, said device including program instructions executable to implement a method comprising: operating network interface card (NIC) agent software on a server computer, said NIC agent software operable to collect performance data indicative of NIC events involving a web page transaction, said NIC agent software customized to collect performance data on tiers of web servers and tiers of NICs; operating client agent software on a client computer, said agent software operable to collect performance data indicative of client events involving the web page transaction, and said client agent software customized to collect performance data on tiers of web servers and tiers of NICs; collecting the information indicative of NIC events, the information indicative of client events; and correlating the information indicative of the NIC events, and the information indicative of client events, to monitor performance of the web page transaction, wherein correlating the information includes grouping events by a client address and by a server address and matching pairs of NIC events and primary web server events by time and data transfer size.
 13. The non-transitory computer readable storage device of claim 12, wherein the method further comprises displaying correlated information to an end user.
 14. The non-transitory computer readable storage device of claim 13, wherein displaying the correlated information from the server comprises displaying information on the an overall operation of one or more web servers.
 15. The non-transitory computer readable storage device of claim 13, wherein displaying the correlated information form the server comprises displaying information on the web page transaction. 